This disclosure relates to flow field plates in a fuel cell. Fuel cells typically include an anode catalyst, a cathode catalyst, and an electrolyte between the anode and cathode catalysts for generating an electric current in a known electrochemical reaction between reactants, such as fuel and oxidant. The fuel cell may include flow field plates with channels for directing the reactants to the respective catalyst. Conventional fuel cells utilize inlet and outlet manifolds to deliver the reactant gases and coolant to the channels and receive exhaust gas and coolant from the channels. The flow field plates are often rectangular, and the inlet and outlet manifolds may be arranged on opposite ends of the plate from one another.
Flow field plates are often designed such that reactants move from one side of the flow field to the other through a first set of channels and turns to flow back across the flow field in another set of channels many times to make at least several passes over the flow field. One challenge associated with a multi-pass design is achieving high fuel cell performance with a configuration that can be stamped. Multi-pass flow field designs in solid plates may employ an embossed feature in the end turns that consists of multiple protrusions. The challenge for these designs is to maintain cell performance which requires good electrical contact and the distribution of fluids to the channels. Failure to achieve these requirements results in poor performance in the flow turn regions which lowers overall cell performance.